A fuel cell operates by creating an electrochemical reaction between incoming fuel and oxidizer streams to create electricity. Many fuel cells, such as solid oxide fuel cells (SOFC), operate at high temperatures. Waste heat created by the electrochemical reaction within a fuel cell must be removed to control the temperature of the fuel cell to prevent failure of the cell. A typical thermal management system includes circulating excess reactant, beyond what is needed for the electrochemical reaction, through the fuel cell to absorb heat. However, in certain applications, such as an airborne application in which a fuel cell is utilized on an aircraft, weight is a primary consideration. Storing the excess reactant required to maintain the temperature of the fuel cell can be weight prohibitive.
Gases exiting the fuel cell can be recirculated back to an incoming reactant stream for cooling purposes. However, doing so requires an additional cooling subsystem to cool the recycled flow due to the heat absorbed from the fuel cell. The additional cooling subsystem results in a more complex control system, additional vehicle thermal load, and an increased weight of the overall system. Another conventional thermal management system includes a separate closed system cooling loop for circulating a stored coolant through the fuel cell and through a cooling subsystem. Similar to the other thermal management systems described above, a separate closed system cooling loop adds additional weight and adds complexity with additional pumps, coolant, lines, and power consumption requirements.
It is with respect to these considerations and others that the disclosure made herein is presented.